1. Field of the Invention
The invention relates generally to delivery systems for interventional devices and, more particularly, to a guiding catheter for delivering an interventional device to an anatomical site.
2. Description of the Related Art
Numerous devices and procedures have been developed for delivering interventional devices to a work site within an anatomical body. Such procedures usually involve the percutaneous introduction of an interventional device into the lumen of an artery, usually through a catheter. Some prior art devices for delivering an interventional device utilize a guiding catheter. The guiding catheter is routed through the vasculature of the anatomical body to a location proximate the work site. The interventional device which is coupled to a delivery device, such as a guide wire, is then routed through the guiding catheter and to the work site. After the interventional device is positioned at the work site, the guiding catheter is removed and the interventional device is deployed, leaving the interventional device in place. In a typical over-the-wire delivery platform the guide wire maybe more than twice the length of the delivery sheath with more than half the length external to the patient during the delivery of the interventional device. This extra length is needed when the guiding catheter is removed from the patient since the guide wire must usually be held in place. Therefore, the portion of the guide wire external the patient must be longer than the guiding catheter to allow the operator to grasp a portion of the guide wire during all stages of removal of the guiding catheter. Due to the length of the guide wire, it may sometimes be necessary to have a second person assist the operator when removing the guiding catheter to prevent the guide wire from shifting within the vessel.
Other guiding catheters include a sheath having at least one longitudinal weakened area in the form of a slit or a perforation along the length of the sheath. Other embodiments include a longitudinal groove along the length of the sheath. The purpose of the slit, groove or perforation is to provide a weakened area along the length of the sheath that can be split so that the sheath may be peeled away from the guide wire, or other delivery device, used to deliver the interventional device. Current peel-away sheaths include two longitudinal slits so that the sheath can be peeled along the slits for removal of the sheath from the guide wire or other delivery device. Guiding catheters utilizing such sheaths make it possible for the sheath to be removed from the anatomical body and the guide wire or other delivery device by just one person.
Although the longitudinal slits, grooves and perforations of current peel-away sheaths promote easy splitting of the sheaths, they also predispose the sheaths to kinking along the thinner cross sections thereby created. The longitudinal slits, grooves and perforations also make it difficult to transfer torsional loads through the sheaths. Kinking of the sheath and poor torque transfer throughout the length of the sheath cause difficulties in routing the sheath through the vasculature.
Hence, those skilled in the art have recognized a need for providing a peel-away sheath that is not susceptible to kinking and that efficiently transfers torsional loads throughout the sheath. The present invention fulfils these needs and others.